Process of building-up and fixing the contour of stencils



Sept. 22, 1936. T. c. slMPsoN 2,054,914v

PROCESS oF BulLDING-UP AND FIXING THE coNToUR oF STENCILS Filed IJuly 15, 1955 sayvrv.

i A mvramon Patented Sept. 22V, 1936 UNITED STAT PROCESS 0F BUILDING-UI AND FIXING THE CONTOUR 0F STENCILS Thone Collinge Simpson, Toledo,

of one-half to Nellie M. Beck,

Ohio, assig'nor Toledo,` Ohio Application July y15, 1935, lserial No. 31,442 `:i claims. (c1. i1-.385)

This invention relates to the process of building up and fixing the contour of photographic stencils for duplicating trade marks, printed matter, drawings, photographs, and for making many colored signs and the like on a commercial scalev Where large quantities of copies are desired, astencil being'needed for each color.

According to vthis invention, the stencil to be built up and fixed in its contour is made from a photographic positive developed from a yiilm of sensitized gelatin and the ordinary carbon tissue is employed and the film transferred to a screen in the manner fully described in U. S. Patent #1,327,931'issued to Sydney James Waters, Esher, England.

This process begins at the point where Mr. Waters left'oi, he having transferred a film to the stencilingmaterial such as a silk screen.

My process consists in making the stencil durable and permanent and in xing the contour of the stencil to any desired `regular or irregular shape and contour.

The silk screen with the image and carbon tissue thereon made according to the process of Waters is exible and may be formed over any shaped contour and fastened thereon, but it is extremely perishable and when used to make a few copies the edges of the image become damaged and worn. This defect is remedied by my process of building up and making the stencil a fixed and hardened shape which is durable and permanent.

Fig. l is a front elevation of a screen stencil complete.

Fig. 2 is a cross section along lines A-A of Fig. 1 of a stencil in process, illustrating the screen and image, only.

Fig. 3 is a cross section along lines A-A of Fig. l illustrating the screen, image, with waxed paper on the back and after the asphaltum has been applied on the front of the screen and image.

Fig. 4 represents a cross section along lines A-A of Fig. 1 with the waxed paper on the back of the stencil removed and a layer of gum substituted for the waxed paper and the gum removed from that part of the back of the stencil through which the screen paste is forced lon the object to be stencilled.

Fig. 5 represents a completed stencil with the layer of gum inposition in cross section along lines A-A of Fig. l with the layer of gum in position, the same as in Fig. 4 but with the asphaltum entirely removed.

Referring to the drawing of the screen, I represents the frame, 2 the silk screen and3 a positive lrn image infwhich B'represent the perforations in theimage', the edges of which. as well as the balance of the surfaces of the film and image it is my purpose toflx and strengthen with my process. f

The first step is to provide a silk screen 2 on a frame I and then place a positive photographic gelatin film on the front side of the screen.V This gelatin image will adhere to the screen if it is placed. on the screen while soft and immediately after the image has been developed in the usual manner of developing photographic images. For the purpose of illustrating an imagein the drawing, I have selected the capital letter: N which is-indicatedby 6. l

In Fig. 3 the building up of the screen has advanced to the placing of a waxed sheet of paper l on the back of the. screen and applying one or more coatings of asphaltum 4 to the front side of the screen. It willV be noted that the asphaltum has filled up the openings 6 in the lm image 3 which form the letter N up to the underside of the waxed sheet 1.

In Fig. 4 the next step in building up the screen is illustrated. The waxed sheet 1 has been removed and a coating of gum 5 has been sprayed or painted over the entire back surface of the screen. The gum will not adhere to the asphaltum which latter projects through the openings of the image and will adhere only to the image and those parts of the screen which are free from asphaltum, but unites with the gelatin part of the image to strengthen it. This is due to the fact that the asphaltum is oily and is soluble only in gasoline, benzine or naphtha, While the gum and gelatin are both soluble in water and when the back of the screen is being covered with the gum, the latter is in solution with water.

In Fig. 5 a completed builtup stencil is shown, ready for use, in which 6 and 8 represent the openings in the image 3 and gum coating 5 respectively.

To make a screen of various contours instead of a straight or flat one, it is only necessary to make a frame which will permit the screen and image to be formed into any regular or irregular shape of the object to be stencilled, by laying the screen and image while soft against the form desired and processing it as above outlined and drying it against the form and contour of the object it is desired to stencil.

The operation of my process after having first placed a sheet of waxed paper on the support having the shape and contour that it is desired for the stencil, comprises placing the back of the liliV which I prefer to use instead of the other Water-U nonsoluble compounds.

The next step in my process is to strip the Wax paper from the back side of the screen by removing it from its support and the screen is then reversed in position and fastened on the support,

after which I paint the back of the screen with a Water-soluble gum such as glue, -ge1atin,letc. and as the asphaltum is waterproof, the gum solution will not affect it in any Wise. The result' is a coating of gum on the back side of the screen which fills the meshes of the screen on that side entirely. The coating of the gum solution is also permitted to dry thoroughly. The coat-V ing of gum however is removed over the openings 8, being the exposed and developed parts of the lm and image 6 of 3.

The'next and last step in my process is to wash the front of the screen with benzole, naphtha or a similar compound to remove the asphaltum, after which the stencil is fixed built up and ready for use and a great quantity of copies may be made therefrom without damaging the outlines of the image. Y

A repetition of the process of painting the soluble gum 'on the stencil will thicken and strengthen it so as to make the stencil permanent and a much heavier coating of screen paste will result. These additional coatings of soluble gum should be applied before the asphaltum is removed.

I claim:

1. The process of building up and xing a film and image on a silk screen for a stencil and forming the contour of the stencil for duplicating purposes consisting of placing the silk screen with the lm and image thereon on a support with a waxed surface against the back of the screen, covering the front side of the screen, film and image with asphaltum, permitting the asphaltum to dry thoroughly, then covering the back side of the screen, lm and image with one or more coats of gelatin and permitting each coat to dry and removing the asphaltum from the screen, lm andimage by washing the face of the screen, iilm and image with benzole.

"2. The process of fixing a stencil on a screen with .a film and image thereon, consisting of covering the back of the screen with a sheet of waxed paper and covering thereverse side of the screen with'asphaltum and when dry, also covering theback side of the screen, film and image With one or more coats of water soluble gum, after removing the sheet of waxed paper from the back of the screen and washing the 'face of the stencil with naphtha to remove the asphaltum.

3. The process of xing and making durable a photographic image on a screen for a stencil consisting of covering the back of the screen with Wax, painting the front of the screen and image With a Water-nonsoluble. material and drying, removing the wax from the back of the screen and covering the back of the screen withV one or more coats of water-soluble material and Washing the face of the screen and image with naphtha to remove the water-nonsoluble material.

THONECOLLINGE SIMPSON. 

